1. Field of the Invention
The present invention relates generally to conferencing and, more specifically, to videoconferencing.
2. Description of the Related Art
Videoconferencing may be used to allow two or more participants at remote locations to communicate using both video and audio. Each participant location may include a videoconferencing endpoint for video/audio communication with other participants. Each videoconferencing endpoint may include a camera and microphone to collect video and audio from a local participant to send to another (remote) participant. Each videoconferencing endpoint may further include a display and speaker to reproduce video and audio received from a remote participant. Each videoconferencing endpoint may also be coupled to a computer system to allow additional functionality into the videoconference. For example, additional functionality may include data conferencing (including displaying and/or modifying a document for two or more participants during the videoconference).
Videoconferencing may involve transmitting video streams between videoconferencing endpoints. The video streams transmitted between the videoconferencing endpoints may include video frames. The video frames may include pixel macroblocks that may be used to construct video images for display in the videoconferences. Video frame types may include intra-frames, forward predicted frames, and bi-directional predicted frames. These frame types may involve different types of encoding and decoding to construct video images for display. Currently, in a multi-way videoconference, a multipoint control unit (MCU) is used to composite video images received from the videoconferencing endpoints onto video frames of a video stream that may be encoded and transmitted to the various videoconferencing endpoints for display.